#!/usr/bin/env node

const pi = Math.PI;

var Circle = function(r){
  this.d = function(){
    return 2 * r;
  }
  this.area = function(){
    return pi * r * r;
  }
  this.circumference = function(){
    return 2 * pi * r;
  }
}

module.exports = Circle;

console.log(module);
